This study aimed to evaluate reproductive potential in women with Turner syndrome (TS), focusing on 45,X/46,XX mosaicism and the impact of mosaic ratio on reproductive outcomes. The study retrospectively analyzed 145 TS patients diagnosed postnatally by peripheral blood karyotyping from January 1990 to May 2023. Karyotypes were categorized into 45,X monosomy, 45,X mosaicism with Y chromosome and 45,X mosaicism without Y chromosome. The predominant karyotype was 45,X/46,XX mosaicism (71.0%), accounting for most cases with preserved reproductive potential. Within this subgroup, spontaneous menarche (SM) occurred in 97.7% of cases with <40% 45,X cells, while 84.2% of pregnancies occurred in those with <10% 45,X cells. Among patients aged ≥15 years with mosaic karyotypes containing 46,XX and no structural abnormalities, SM occurred in 95.3% of those with <40% 45,X cells, but in none with ≥40% (p < 0.001). In contrast, cases of 45,X monosomy, Y-containing mosaicism, structural X abnormalities, 45,X/46,X with marker chromosomes or 45,X/47,XXX showed no pregnancies and minimal SM. Recurrent pregnancy loss (RPL) was the diagnostic indication in 34% of cases, likely enriching milder mosaicism. Women with 45,X/46,XX mosaicism retain reproductive potential, particularly when 45,X cell ratios are low. Early diagnosis via peripheral blood karyotyping supports timely fertility counseling and ovarian care. Turner syndrome (TS) is a genetic condition in females caused by the complete or partial loss of one sex chromosome. It can affect growth, development and fertility. Mosaicism refers to a condition where an individual has more than one genetically distinct cell line in their body, all derived from a single fertilized egg. In TS, this might mean that some cells are missing part or all of an X chromosome, while others carry different sex chromosome patterns like 46,XX, 47,XXX or other combinations. This study examined how different TS karyotypes, especially mosaic forms, relate to spontaneous menarche (SM) and pregnancy. We reviewed the records of 145 women diagnosed at a tertiary medical center in Taiwan. Most had mosaic TS without a Y chromosome. We found that patients with a lower percentage of 45,X cells were more likely to have SM and conceive. Among 53 women with pregnancy history, most had fewer than 10% of 45,X cells, although pregnancies were also seen in those with higher levels. In contrast, patients with non-mosaic TS or structural X abnormalities seldom had SM or achieved pregnancy. Our findings emphasize the value of detailed chromosome analysis and early counseling to support reproductive and hormonal health in women with TS. Early diagnosis and support can help improve reproductive planning and long-term care for women with TS.

Since the first description of Turner syndrome (TS), both genotypic spectrum and phenotypic presentation have evolved. This study aimed to examine trends in this evolution over the past three decades and provides an overview of current genetic and clinical features in a large nationwide multicenter cohort of girls with TS. We analyzed data from growth hormone (GH)-treated girls with TS included in BELGROW, the national GH registry of the BELux Society for Pediatric Endocrinology and Diabetology, between 1985 and 2022. Karyotype, age at diagnosis, and phenotype were studied in 716 girls. Two periods were compared: 1991-2002 (group 1, n = 250) and 2003-2017 (group 2, n = 270). The annual number of girls with TS starting GH remained stable (mean n = 19/year). In the entire cohort, monosomy 45,X was the most frequent karyotype (44%), followed by structural anomalies of the X chromosome (27%), 45,X/46,XX mosaicism (13%), triple X mosaicism (4%), 45,X/46,XY or complex Y anomalies (6%), and others (6%). The proportion of 45,X decreased between the two periods (46%-38%, p < 0.05). Overall, median age at diagnosis was 6.4 years with 7.6% of girls diagnosed prenatally, 24% before age 1, 49% in childhood, and 19% after 12 years. Prenatal diagnoses increased from 2.5% (group 1) to 15% (group 2) (p < 0.001). Girls with a 45,X karyotype were diagnosed earlier than girls with other genotypes (median 2.2 vs. 8 years, p < 0.001). Skeletal (73%), neurosensory (60%), and cardiac (29%) systems were most affected. Skeletal and cardiac malformations were more frequent in girls with a 45,X karyotype (p < 0.05 and p < 0.01, respectively). Genotype distribution and timing of TS diagnosis have significantly changed since 1991, while the annual number of girls starting GH therapy has remained stable. A 45,X karyotype is associated with earlier diagnosis and more comorbidities.

The prevalence, incidence, and associated factors of liver disease (LD) in Turner syndrome (TS) remain uncertain. A meta-analysis was performed to quantify LD burden in TS. Four electronic databases were searched through June 2025 for observational studies involving karyotype-confirmed individuals with TS. LD was defined by raised serum liver enzymes (RLE), International Classification of Diseases codes, imaging, or histology. Pooled prevalence, incidence, and odds ratios (OR) with 95% confidence intervals (CI) were calculated. Forty studies from 19 countries with aggregate data on 9728 young TS individuals (median age 25.5 years, IQR 16.8-30.7) were included. Prevalences of RLE, steatotic LD (SLD), and significant/advanced liver fibrosis were 26.9% (95% CI 19.7-35.6), 22.3% (9.9-42.9), and 12.2% (2.6-41.7), respectively. Incidence of RLE was 16.7 per 1000 person-years (7.6-36.8). Compared to age-matched healthy controls, TS individuals had higher odds of RLE (OR 3.96 [95% CI 1.45-10.84]), SLD (OR 4.03 [1.86-8.70]), and significant/advanced fibrosis (OR 5.74 [2.99-11.01]). Compared to X monosomy, isochromosome Xq conferred a higher risk of RLE (OR 1.55 [1.15-2.10]), while mosaicism without structural abnormalities was protective (OR 0.54 [0.32-0.89]). Ring X or Y chromosome material carried risks like X monosomy. Hormone replacement therapy was not associated with an increased risk of RLE (OR 1.10 [0.79-1.53]). Liver disease is common in individuals with TS, with a 4-6 times higher risk than age-matched healthy females. X chromosome abnormalities are more strongly associated with an increased liver disease risk than hypogonadism.

Turner syndrome (TS) is the most common sex chromosome abnormality disorder, caused by complete or partial absence of the X chromosome, its clinical manifestations primarily include short stature, gonadal dysgenesis, and characteristic cardiovascular malformations, pediatric cardiologists pay particular attention to coarctation of the aorta (CoA), which occurs in 15%-30% of TS patients and represents a life-threatening condition requiring prioritized screening during the neonatal and childhood periods (1- 3). Furthermore, due to lymphatic system developmental abnormalities, TS patients also face elevated risks of aortic root dilation, bicuspid aortic valve, and vascular structural anomalies (3). Pulmonary arteriovenous malformation (PAVM) is a rare pulmonary vascular anomaly, with an estimated prevalence of approximately 1 in 50,000 in the general population (1-3). Although the exact prevalence of PAVM in TS patients remains unclear, case series suggest a significantly elevated risk compared to the general population (estimated risk ratio: 5- to 10-fold), this association may be attributed to defective vascular elastic fiber development and dysregulated angiogenic signaling pathways in TS patients (4, 5). Here, we report the first documented case of TS complicated by PAVM, aiming to enhance clinicians' awareness of this rare comorbidity and provide evidence-based diagnostic and therapeutic recommendations.

Turner syndrome (TS) is a sex chromosome disorder affecting phenotypic females who have one intact X chromosome and a completely or partially missing second sex chromosome. It was first described approximately a century ago by Seresevskij, Ullrich and Turner. However, the cytogenetic basis of TS was only reported by Ford in 1959 following Tjio and Levan's optimisation of chromosome visualisation. TS karyotypes include classic monosomy X (40%-50%); monosomy X mosaicism (3%-25%); isochromosome X (10%-18%); ring X (10%-16%); mosaicism for monosomy X and a normal or structurally abnormal Y chromosome (6%-12%); deletion Xp (< 5%) and unbalanced X-autosome translocation (< 2%). While parental age does not affect the complete loss of one X chromosome, the paternal X chromosome is absent in three-quarters of patients with TS. Clinically, detecting the parental origin of the remaining X chromosome is not currently useful in routine TS care. Recurrence risk is low for phenotypically normal parents with a child diagnosed with TS. Pregnancy loss is the outcome for the majority (~99%) of TS cases; however, prenatal ultrasound findings for foetuses with TS may include abnormalities like cystic hygroma and hydrops. Postnatal phenotype for patients with TS includes short stature, delayed puberty, ovarian dysgenesis, hypergonadotropic hypogonadism, infertility, cardiac defects, endocrine, metabolic and autoimmune disorders. This review aims to outline clinical indications for testing, describe test methodologies, provide genetic test result examples that highlight complex TS karyotype diagnoses, summarise clinical management options and discuss the phenomenon of 'normal' sex chromosome loss with advancing age.